The frequency of using The Ordinary Salicylic Acid Serum depends on your skin type and tolerance to the product. Salicylic acid is a beta-hydroxy acid (BHA) that can effectively exfoliate the skin and help unclog pores. However, it can also be drying and irritating if overused.

For most people, using The Ordinary Salicylic Acid Serum once or twice a week is sufficient to achieve the desired results without causing excessive dryness or irritation. Start by using it once a week and gradually increase the frequency if your skin tolerates it well.

If you have particularly oily or acne-prone skin, you may be able to use it more frequently, up to every other day. However, it's important to pay attention to how your skin reacts and adjust the frequency accordingly. If you experience any excessive dryness, redness, or irritation, reduce the frequency of use or discontinue use altogether.

Remember to always follow the instructions provided by the brand and consult with a dermatologist if you have any concerns or specific skin conditions.